Not a Malcom, but I have quite a bit of experience with the tasco.
I did not like the adjustments and base set up on mine, so I had me tool and die buddy build me a set .
He made three, but I think they are all gone.
Here's some pics.
This is a a 40/65 Uberti BTW, and my buddy here is shooting it at 400 yards across the river at a 1 foot square rock - yup, he hit it!
The mounts are fully adjustable, and lock up as well.
I sold a set of the mounts to a guy who put them on a malcom BTW, and he was VERY pleased with them.
David

I've used the scopes from Montana Vintage Arms for BPCR silhouette and they're a great piece of kit. I've only shot in one scope match (using a friend's Rolling Block) and as I recall I did pretty well (the match was almost a year ago now). I've never used the Leatherwood so I can't comment on it. The MVA will run you $950 to $1100 for the scope which includes mounts. Not cheap but you never regret buying good optics. I'm still young and see well enough to use aperture sights, but the Old Man (71 years) is thinking the scope would make life a lot easier for him.